Quiz 7 &8

A single mutation causes sickle-cell disease. Which of the following statements best describes how this occurs

A single nucleotide mutation causes a normal glutamine amino acid to be replaced with a valine amino acid. This causes the resulting hemoglobin protein to form incorrectly, resulting in sickle-shaped red blood cells that cannot function as intended.

What is the difference between a gene and an allele? Select the best answer.

Alleles are specific forms of genes, and may be dominant or recessive.

Which of the following statements best describes the structure of a hemoglobin molecule?

Hemoglobin is composed of four globin molecules, each with their own heme group that binds to and carries oxygen.

What is NOT a component of the translation machinery?

RNA polymerase

DNA strands are complementary of each other. This means if one strand has an adenine the other has a __________, and if one strand has a guanine the other has a/an __________.

Thymine;cytosine

Which of the following best explains the role of transcription in a cell?

To produce a mRNA molecule to deliver the genetic instructions outside the nucleus.

The processes of transcription and translation are collectively known as

gene expression.

When a gardener crosses a plant with red flowers with a plant with yellow flowers, orange-flowered offspring result. What mode of inheritance is exemplified by these flowers?

incomplete dominance

In gene expression, the goal of translation is to

read codons and incorporate corresponding amino acids into a growing polypeptide chain.

Complete the following sentence: Hemoglobin functions in ______ cells and carries ______ to all cells of the body.

red blood; oxygen

DNA replication is considered to be ______ because the end product consists of one old strand and one newly synthesized strand.

semiconservative

During translation, a polypeptide chain is created using an RNA template. Which of the following components is responsible for bringing amino acids to the growing polypeptide chain?

tRNA

During DNA replication, the ______ strand is the one being used by the DNA polymerase to provide the new ______ strand of DNA.

template; daughter

The information contained in genes is expressed

through transcribing the DNA segment into mRNA. by translating the mRNA into a polypeptide. by folding the polypeptide into a structural protein.

PCR is important because it allows scientists to

track ancestry of organisms. identify criminals in forensic studies mimic DNA replication to copy a specific segment of DNA to study.

Some forms of hypercholesterolemia are an example of incomplete dominance in humans. In a couple of two heterozygous individuals for the responsible allele have a child, what is the probability of that child to have a severe hypercholesterolemic disease?

25

How many nucleotides are contained in a single codon?

3

If a DNA template strand has a sequence of 3′ TACAATGTAGCC 5′, the RNA produced from it will be which sequence?

5'AUGUUACAUCGG 3'

Consider sickle cell disease as an example of recessive genetic disease with complete dominance inheritance. A woman with sickle cell disease has children with a man who has sickle cell trait (is a carrier). What is the probability of having a child with sickle cell disease? Hs : allele for sickle cell disease

50

In deer, albinism is a recessive trait. If a deer that is heterozygous for albinism has offspring with a deer that is albino, what is the possibility that they will have an albino fawn?

50%

Most human sex-linked traits are carried on the Y chromosome

False

Phenotypic ratios are always equal to genotypic ratios.

False

Consider sickle cell disease as an example of recessive genetic disease with complete dominance inheritance. A woman with sickle cell disease has children with a man who has sickle cell trait. What is the genotype of the gametes the mother can produce? Hs : allele for sickle cell disease Hn:normal allele

Hs

In eukaryotic cells, transcription occurs in the ______.

Nucleus

Sickle-cell disease has a physiological impact on the body because it

changes the shape of red blood cells, which decreases the oxygen supply to the tissue. decreases the amount of oxygen picked up by red blood cells from the alveoli. can cause anemia to develop.